In 1892 a hidden lake trapped inside a glacier on the French side of Mont Blanc
suddenly burst and inundated the populated valley below in the greatest natural
disaster ever recorded in the Alps. No one knows if a similar cataclysm is now
imminent. NOVA ventures deep inside the glacier itself to find out and explores
a uniquely beautiful and dangerous environment with a new breed of explorer
known as the "glacionaut."

"Descent Into the Ice" is the latest installment in NOVA's High
Adventure series, which has already taken viewers to the tallest mountains
in Asia, Antarctica, and Africa, and now probes Mont Blanc, the highest point
in western Europe. The program is a Journey to the Center of the
Earth-style voyage into the eerie inner world of glacial cracks, crevasses,
ice shafts, pits, water wells, and tunnels, as glacionauts search for evidence
of hidden lakes that form through the intricate action of melting ice.

Mont Blanc is French for "white mountain," an apt name for the snow-covered
peak rimmed by massive glaciers that formed 10,000 years ago during the last
ice age. The glaciers have been slowly melting ever since, creating a labyrinth
of ice caves and concealed lakes that threaten all who live downslope. On July
12, 1892, 200 vacationers and residents of the Alpine town of Saint Gervais
died when one of these lakes suddenly and catastrophically emptied, sending a
tidal wave of water plunging down the narrow gorge onto the sleeping
villagers.

Because the lakes form deep within the glaciers, they are virtually
undetectable except by those willing to descend the shafts, called water wells,
that feed meltwater into a maze of natural features threading their way to
concealed caverns. NOVA's cameras accompany French glaciologist Luc Moreau and
German photographer and adventurer Carsten Peter as they probe Mont Blanc's
thousand-foot-thick Mer de Glace ("Sea of Ice") as well as the mountain's
Argentiere Glacier, the second largest glacier in France.

At various stages, Moreau and Peter rappel, climb, raft, and scuba dive through
the icy wilderness. The underwater dive is the first ever on Mont Blanc, a
bone-chilling experience made all the more perilous when the breathing
apparatus freezes. Members of the scientific team also resort to a century-old
technique to measure the speed of water flow within the glacier. By introducing
a potent dye at the top, they can determine the time it takes for the color to
reach the bottom, allowing the glacionauts to fill in the picture of what
exactly is happening on the inside.

In "Descent Into the Ice," specialists in glacial hazards rappel deep inside a glacier on Mont Blanc in search of a concealed lake.